1. Field of the Invention
The invention is directed toward the field of packetized networks, and more particularly, to monitoring of the type of transport service requested of a packetized network, and more particularly to the monitoring and selective discouragement of non-elected transport service over a packetized network.
2. Related Art
The recent growth in wide area packetized networks has been dramatic. Two examples of such wide area packetized networks are the various wireless communication technologies and the Internet. An advantage of such packetized networks is that a large variety of information can be transmitted over the same network. For example, pure data files such as electronic mail (E-mail) or interactive world wide web (www) sessions, telephone calls and video images can all be transferred over the Internet.
Much of the packet traffic over a network does not have delay-sensitive content. However, voice packets and video packets are real-time packets. Real-time packets are very sensitive to delay. For voice and video, if more than a few packets are significantly delayed, then the received voice or video transmission is perceptibly (to the user), i.e., degraded in quality.
Some of the routers in packetized networks attempt to treat delay-sensitive packets with a higher priority than delay-tolerant data packets. A user requesting the transport of delay-tolerant data packets is usually unaware or does not care that his packets have been delayed in favor of, e.g., voice or video packets. When the packetized network becomes congested, the differences in delay between preferential and non-preferential packets increase.
Packet networks typically differentiate tariffs based on rate and/or a maximum delay bound or not at all. Currently network operators sell higher value transport services with packet delay guarantees, but have no way of coaxing users to use them when the network is uncongested. Internet access is typically sold either at a flat rate, or based on the transmission bandwidth/modem speed. If users experience low delays for all their traffic, there is no incentive to subscribe or use a higher cost transport service that guarantees lower delays.
So, currently, the cost of access to a packetized network such as the Internet is not affected by the type of packet transport service that a user wishes to request. Someone wishing to use the network for packetized voice transmissions pays the same subscriber fee as someone wishing to transfer files. In other words, a user pays the same amount to transport delay-sensitive packets as delay-tolerant packets. Yet, as discussed above, packetized networks tend to treat these types of packets differently. Still, the user transporting delay-sensitive packets does not pay a premium as compared to the user transporting delay-tolerant packets.
It is known to filter out and prevent some types of packets in a packetized network from reaching their destinations. Firewalls are devices or programs inserted into a network to permanently prevent certain packets from passing through. A firewall decides whether to let a packet pass through or not by inspecting the various header fields contained in a packet. If one would have attempted to adapt firewall technology to discourage use of a network that did not comply with a preexisting service election, then non-compliant packets would have been intercepted and prevented from reaching their destination.
This is so drastic as to undermine the user""s confidence in the services of the network provider.
A first form of the invention is directed toward a method, device, and article of manufacture (software) for monitoring whether the use of a packetized network is commensurate with a preexisting transport service election designated for a user. This embodiment receives packets associated with the user. Such packets have at least one parameter indicative of a transport service selection required by the respective packets or omit a parameter indicative of a required transport service, where the omission also can be considered indicative of the required transport service. After receiving the packets, the embodiment identifies those packets for which the required transport service does not comply with the preexisting transport service election. The identification is preferably performed by comparing the at least one parameter of the received packets with a list of reference values that are representative of the preexisting transport service selection.
A second form of the invention is directed toward a method, device, and article of manufacture (software) for selectively discouraging the use of a packetized network that is not commensurate with a preexisting quality of service selection that has been made by the user. Similar to the first embodiment, this embodiment receives packets associated with the user and determines those packets for which the required quality of service does not comply with the preexisting quality of service selection. The second embodiment then delays arrival of at least some of the non-compliant packets by durations that are sufficient to discourage similar non-compliant use of the packetized network. Compliant packets, e.g., electronic mail (Email) packets, are passed along without delay. For the type of non-compliant transport services being requested, preferably only the minimum number of packets are delayed which are sufficient to produce a user-perceptible degradation in the quality of the service. This minimizes the size of the buffer required. Again, preferably, the determination of non-compliance involves comparing the at least one parameter (or absence thereof) in the received packets with a list of reference values representative of the preexisting transport service election, as well as culling those received packets for which the at least parameter is inconsistent with the list of reference values.
In the second form of the invention, the durations of the delays, respectively, can be determined, e.g., as a function of the required minimum quality of service, and/or as a function of the time (hour and day of the week) at which the non-compliant packets are received, respectively, and/or as a function of a random number, and/or as a function of the instantaneous congestion in the packetized network.
In the second form of the invention, the delay can be implemented by buffering the non-compliant packets in a memory or by intentionally lengthening a route of the non-compliant packets to their respective destinations. An example of intentionally lengthening the route of a non-compliant packet is to send the non-compliant packet through a closed loop at least once.
In the first and second forms of the invention, the at least one parameter of the packet under consideration can correspond to a field of the packet representing the destination address, a field representing a source address, a field representing a mapping to at least one of a source application and a destination application, a field representing a predefined flow of packets, a field representing a type of encapsulated higher level protocol, and a field representing additional protocol options.
In the first and second forms of the invention, the user can be the originator of the received packets or can be the intended recipient of the received packets. In both the first and second embodiments, in addition to identifying packets that are non-compliant, questionable packets are identified. A questionable packet is one for which the compliance of the required transport service selection with the preexisting service selection is indeterminate, e.g., because of encryption. The questionable packets are also delayed by durations sufficient to discourage similar questionable use of the packetized network.
A third form of the invention is also directed toward a method, device and article of manufacture (software) for discouraging use of a packetized network that is not commensurate with a preexisting quality of service election that has been made by a user. Packets are received and it is determined which of the received packets are associated with the user. The arrival of at least a predetermined fraction, if not all, of the packets associated with the user is delayed, again, to discourage use that could be affected by such delay. The delay is not so great as to degrade basic service.
An advantage of the present invention is that it presents a technology that network service providers can use to police or to selectively encourage compliance with the quality of service elected by a user. As such, the packetized network service providers can price their services at different rates per type of service used or consumed by the user. In other words, the invention makes quality of service fee differentiation for a packetized network viable despite the circumstance that the network could transport all packets with low delay.
Again, the technique according to the invention is especially useful for networks or connections with light or moderate traffic load where different transport services experience similar delays. It permits a network operator or access provider to extend low cost transport services only for delay tolerant traffic and induce users to subscribe to or use additional or alternative value added transport service levels for their delay sensitive traffic. As an example, the transport services offered to an access subscriber could be segmented as follows: large delay for large file transfers and Email; medium delay for interactive transfers such as world wide web (WWW) traffic; and small delay for interactive video, IP telephony and teleconferencing.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.